Geneva, Switzerland and Boston, MA - 01 March 2018 - ObsEva SA (Nasdaq: OBSV), a Swiss biopharmaceutical company focused on the development and commercialization of novel therapeutics for serious conditions that compromise a woman's reproductive health and pregnancy, today announced it will make presentations at the 65th Annual Meeting of the Society for Reproductive Investigation (SRI), taking place March 6 - 10, 2018 in San Diego, CA. These presentations will include the following:

First-in-women (FIW) clinical safety and exposure data following single and multiple oral doses of prostaglandin F2alpha (PGF2alpha) receptor antagonist, OBE022, showing the favorable safety and pharmacokinetic profile of OBE022. In addition, the absence of a clinically relevant effect of food on the absorption of OBE022 will be described (Poster presentation S-038, Saturday March 10th, 2018).

"We are delighted to be able to update the scientific community on the progress of our preterm labor drug candidate OBE022." commented Ernest Loumaye, MD, PhD, OB/GYN, CEO and Co-Founder of ObsEva.

"The first administration of a drug candidate to humans always constitutes a major milestone in the development of a drug. Our clinical trial results to date show predictable exposures within the pharmacologically relevant range, including the absence of a food effect that is key for addressing acute PTL. Importantly, results also support an excellent safety profile, with an absence of adverse effects on the fetus, in contrast to nonspecific prostaglandin synthesis inhibitors that may be used as off label tocolytic therapy, such as indomethacin."

In December of 2017, ObsEva announced the initiation of a Phase 2a study of OBE022 in pregnant women with spontaneous preterm labour with a gestational age between 24 0/7 and 33 6/7 weeks (PROLONG, NCT03369262).

About Preterm Labor

Preterm labor, defined as the birthing process starting prior to 37 weeks of gestation, is a serious condition characterized by uterine contractions, cervical dilation and rupture of the fetal membranes that can lead to preterm birth. According to a study published in the Lancet in 2012, approximately 15 million babies were born before 37 weeks of gestation in 2010, accounting for 11.1% of all live births worldwide. Over 1 million children under the age of five died in 2013 worldwide due to preterm birth complications, and many infants who survive preterm birth are at greater risk for cerebral palsy, delays in development, hearing and vision issues, and often face a lifetime of disability. The rates of preterm births are rising in almost all countries with reliable data for preterm birth, and are associated with an immense financial impact to the global healthcare system.

To date, only treatments with limited efficacy or restrictive safety issues are available to treat preterm labor. In the United States, no drugs are approved for acute treatment of PTL and recommended off-label tocolytic treatments (medications that inhibit labor) include beta-adrenergic receptor agonists, calcium channel blockers, or NSAIDs, which are used for short-term prolongation of pregnancy (up to 48 hours) to allow for the administration of antenatal steroids (e.g. betamethasone). Magnesium sulfate, used for fetal neuroprotection can also be used (up to 48 hours) to inhibit acute preterm labor. Approved tocolytic treatments in Europe include beta-adrenergic agonists, which carry severe maternal cardiovascular risks, and intravenous infusions of atosiban (an oxytocin receptor antagonist).

While prostaglandin inhibitors (NSAIDs) have been shown to be effective for inhibiting preterm labor, use of such drugs is limited, due to the threat of serious and sometimes life-threatening side effects in the fetus. Such side effects may include kidney function impairment, premature constriction of the blood vessel connecting the pulmonary artery and the descending aorta in a developing fetus, and higher risk of thrombosis of the intestinal arteries (a condition called necrotizing enterocolitis).

About OBE022 and PGF2alpha

ObsEva is developing OBE022, a potential first-in-class, once daily, oral and selective prostaglandin F2alpha receptor antagonist, which is designed to control preterm labor by reducing inflammation, decreasing uterine contractions, preventing cervical changes and fetal membrane rupture without causing the potentially serious side effects to the fetus seen with non-specific prostaglandin synthesis inhibitors (NSAIDs). PGF2alpha is believed to induce contractions of the myometrium and also upregulate enzymes causing cervix dilation and membrane rupture. In nonclinical studies, ObsEva has observed that OBE022 markedly reduces spontaneous and induced uterine contractions in pregnant rats without causing the fetal side effects seen with prostaglandin inhibitors such as indomethacin.

About ObsEva

ObsEva is a clinical-stage biopharmaceutical company focused on the clinical development and commercialization of novel therapeutics for serious conditions that compromise a woman's reproductive health and pregnancy. Through strategic in-licensing and disciplined drug development, ObsEva has established a late-stage clinical pipeline with development programs focused on treating endometriosis, uterine fibroids, preterm labor and improving ART outcomes. ObsEva is listed on The NASDAQ Global Select Market and is trading under the ticker symbol "OBSV". For more information, please visit www.ObsEva.com.

Cautionary Note Regarding Forward-Looking Statements

Any statements contained in this press release that do not describe historical facts may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as "believe", "expect", "may", "plan," "potential," "will," and similar expressions, and are based on ObsEva's current beliefs and expectations. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the conduct of clinical trials and related interactions with regulatory bodies, ObsEva's reliance on third parties over which it may not always have full control, and other risks and uncertainties that are described in the Risk Factors section of ObsEva's Annual Report on Form 20-F for the year ended December 31, 2016, and other filings ObsEva makes with the SEC from time to time. These documents are available on the Investors page of ObsEva's website at http://www.obseva.com. Any forward-looking statements speak only as of the date of this press release and are based on information available to ObsEva as of the date of this release, and ObsEva assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise.